using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Moonlight.Api.Database;
using Moonlight.Api.Database.Entities;
using Moonlight.Api.Mappers;
using Moonlight.Shared;
using Moonlight.Shared.Http.Responses;
using Moonlight.Shared.Http.Responses.Users;

namespace Moonlight.Api.Http.Controllers.Admin;

[ApiController]
[Authorize(Policy = Permissions.Roles.Members)]
[Route("api/admin/roles/{roleId:int}/members")]
public class RoleMembersController : Controller
{
    private readonly DatabaseRepository<User> UsersRepository;
    private readonly DatabaseRepository<Role> RolesRepository;
    private readonly DatabaseRepository<RoleMember> RoleMembersRepository;

    public RoleMembersController(
        DatabaseRepository<User> usersRepository,
        DatabaseRepository<Role> rolesRepository,
        DatabaseRepository<RoleMember> roleMembersRepository
    )
    {
        UsersRepository = usersRepository;
        RolesRepository = rolesRepository;
        RoleMembersRepository = roleMembersRepository;
    }

    [HttpGet]
    public async Task<ActionResult<PagedData<UserDto>>> GetAsync(
        [FromRoute] int roleId,
        [FromQuery] int startIndex, [FromQuery] int length,
        [FromQuery] string? searchTerm
    )
    {
        // Validation
        if (startIndex < 0)
            return Problem("Invalid start index specified", statusCode: 400);

        if (length is < 1 or > 100)
            return Problem("Invalid length specified");

        // Query building

        var query = RoleMembersRepository
            .Query()
            .Where(x => x.Role.Id == roleId)
            .Select(x => x.User);

        // Filtering
        if (!string.IsNullOrWhiteSpace(searchTerm))
        {
            query = query.Where(x =>
                EF.Functions.ILike(x.Username, $"%{searchTerm}%") ||
                EF.Functions.ILike(x.Email, $"%{searchTerm}%")
            );
        }

        // Pagination
        var items = query
            .OrderBy(x => x.Id)
            .Skip(startIndex)
            .Take(length)
            .ProjectToDto()
            .ToArray();

        var totalCount = await query.CountAsync();

        return new PagedData<UserDto>(items, totalCount);
    }

    [HttpGet("available")]
    public async Task<ActionResult<PagedData<UserDto>>> GetAvailableAsync(
        [FromRoute] int roleId,
        [FromQuery] int startIndex, [FromQuery] int length,
        [FromQuery] string? searchTerm
    )
    {
        // Validation
        if (startIndex < 0)
            return Problem("Invalid start index specified", statusCode: 400);

        if (length is < 1 or > 100)
            return Problem("Invalid length specified");

        // Query building

        var query = UsersRepository
            .Query()
            .Where(x => x.RoleMemberships.All(y => y.Role.Id != roleId));

        // Filtering
        if (!string.IsNullOrWhiteSpace(searchTerm))
        {
            query = query.Where(x =>
                EF.Functions.ILike(x.Username, $"%{searchTerm}%") ||
                EF.Functions.ILike(x.Email, $"%{searchTerm}%")
            );
        }

        // Pagination
        var items = query
            .OrderBy(x => x.Id)
            .Skip(startIndex)
            .Take(length)
            .ProjectToDto()
            .ToArray();

        var totalCount = await query.CountAsync();

        return new PagedData<UserDto>(items, totalCount);
    }

    [HttpPut("{userId:int}")]
    public async Task<ActionResult> AddMemberAsync([FromRoute] int roleId, [FromRoute] int userId)
    {
        // Check and load role
        var role = await RolesRepository
            .Query()
            .FirstOrDefaultAsync(x => x.Id == roleId);

        if (role == null)
            return Problem("Role not found", statusCode: 404);

        // Check and load user
        var user = await UsersRepository
            .Query()
            .FirstOrDefaultAsync(x => x.Id == userId);

        if (user == null)
            return Problem("User not found", statusCode: 404);

        // Check if a role member already exists with these details
        var isUserInRole = await RoleMembersRepository
            .Query()
            .AnyAsync(x => x.Role.Id == roleId && x.User.Id == userId);

        if (isUserInRole)
            return Problem("User is already a member of this role", statusCode: 400);

        var roleMember = new RoleMember
        {
            Role = role,
            User = user
        };

        await RoleMembersRepository.AddAsync(roleMember);

        return NoContent();
    }

    [HttpDelete("{userId:int}")]
    public async Task<ActionResult> RemoveMemberAsync([FromRoute] int roleId, [FromRoute] int userId)
    {
        var roleMember = await RoleMembersRepository
            .Query()
            .FirstOrDefaultAsync(x => x.User.Id == userId && x.Role.Id == roleId);

        if (roleMember == null)
            return Problem("User is not a member of this role, the role does not exist or the user does not exist",
                statusCode: 404);

        await RoleMembersRepository.RemoveAsync(roleMember);

        return NoContent();
    }
}